An Ancient Micro-Continent?
It has long been speculated that volcanic debris may hold clues to ancient continents buried deep under the layers of our Earth. When Norwegian geologist Bjorn Jamtveit and his colleagues had a layover in Mauritius as part of their research expedition, they decided to test the theory.
Mauritius, an island in the Indian Ocean, rose up as a result of volcanic activity about 9 million years ago. Jamtveit’s team collected sand samples from the beach and sent them for analysis. Imagine their surprise when zircon crystals in the sand were found to be between 660 million and 2 billion years of age!
An underground Atlantis?
Geologists speculate that this may be remains of Mauritia – a micro-continent that was once part of a larger continental mass that included Africa, Madagascar and India put together. As landmasses drifted and were shaped by the Earth’s forces, it is possible that a small piece of this ancient continent was swallowed by water and lost to history.
When the island of Mauritius was formed much later from volcanic activity, the hot magma might have brought out pieces of this ancient continent. The volcanic rocks were weathered down by force of nature, leaving behind hardy zircon crystals!
A brief history of Supercontinents
Did you know that the very first landmass on Earth was too small to be called a continent? Geologists call them cratons. Ur, the very first landmass, may have been no bigger than Australia. Fragments of it live on as part of India, Australia and Madagascar.
Then some time between 1.2 to 1 billion years ago, fragments of our Earth’s crust started to assemble into one giant supercontinent, surrounded by the ocean. Geologists call this very first supercontinent Rodinia. Much of the landscape would have been a rusty-red color, much like Mars today, and life nothing more than single-celled algae.
With the constant geologic and volcanic activity shaping our Earth’s masses, Rodinia likely broke apart 350 million years ago. Over time, it re-assembled to form Panagea, which again broke apart 250 million years ago to form two huge landmasses -- Laurasia in the Northern Hemisphere and Gondwanaland in the Southern Hemisphere.
North America, Europe and Russia were formed from Laurasia. Gondwanaland gave birth to the continents of South America, Africa, India and Australia. Geologists speculate that while India was separating from the continent of Africa and the island of Madagascar, the tiny microcontinent of Mauritia was left homeless.. and drifted to the bottom of the sea.
Courtesy BBC, Wikipedia, io9